Light Output Ratio
In the lighting world “efficiency” is the measurement of the quantity of useful light that is output by a particular light fitting. The industry standard term of measurement is the Light Output Ratio and the abbreviation is LOR which is expressed as a percentage of the total light output. LOR information is usually only available for architectural light fittings, particularly those designed for commercial use and will appear on the manufacturers’ data sheets and on their websites. As a Lighting Designer I use this information to compare the efficiencies between different light fittings and you can do the same. Simply, the higher the LOR percentage, the more efficient the light fitting is, as more light is being distributed out from it.